Non-invasive imaging technologies allow images of the internal structures of a patient or object to be obtained without performing an invasive procedure on the patient or object. In particular, technologies such as computed tomography (CT) use various physical principles, such as the differential transmission of x-rays through the target volume, to acquire image data and to construct tomographic images (e.g., three-dimensional representations of the interior of the human body or of other imaged structures).
Modern CT systems include automatic exposure control (AEC) configured to set the dose operating point to achieve optimized performance between image quality and radiation dose. Typically, automatic exposure control involves modulating a tube current applied to an x-ray source during a scan, so that the lowest necessary radiation dose is delivered while maintaining a desired image quality.
However, some CT imaging modes preclude tube current modulation. For example, for dual energy imaging, the x-ray source rapidly switches between different peak tube kilovoltages (kVp) in order to resolve different materials within the subject being scanned. Due to the rapid kVp switching, the generator may not allow modulation of the tube current. Furthermore, for some imaging scenarios, physical constraints of tube current modulation may render such an approach insufficient for automatic exposure control.